In order to connect a line or lines, e.g. wire, chain or synthetic (such as polyester), lines for the installation, mooring or anchoring of equipment used subsea or underwater, e.g. in oil, gas, offshore wind and tidal energy industries, there needs to be a means of connecting and disconnecting the line or lines. Uses include installing a small subsea structure which can be lifted from the rear or back of a boat or from a rig and lowered to the sea-bed, through to permanent mooring of a floating production structure. On top-side this is straight-forward; however, when subsea beyond diver depth there needs to be a means or device such that a remotely operated vehicle (ROV) may both connect and disconnect the line. There are several such devices known in the art. However, these suffer from a number of short-comings or disadvantages. Even when not operating beyond diver depth, such a device may be desired, since many operators do not want to use divers even where practical. There is therefore a need for a new, simple, robust and easy to use connector.
A known device is the Delmar Subsea Connector as described in U.S. Pat. No. 6,158,093 (DELMAR SYSTEMS, INC.), the content of which is incorporated herein by reference. The Delmar connector requires buoyancy/heave compensation for installation, and is manufactured as a casting which rules such out of some projects. Further, the Delmar connector has no inherent alignment and is similar to a loose shackle.
Another known type of connector is the so-called ball and taper connector. Such are commercially available from Balltec Limited (www.balltec.com) as MoorLok™ and from First Subsea Limited (www.firstsubsea.com) as Ballgrab™. The Balltec connector is described in WO 2006/109065 A1, the content of which is incorporated herein by reference.
Ball and taper connectors utilise the ball and taper principle as schematically illustrated in FIG. 1. The ball and taper connector 5 comprises a male portion or mandrel 10 and a female portion or receptacle 15. The male portion 10 carries a ball cage 20 and a plurality of balls 25. When the male portion 10 and ball cage 20 enter the female portion 15 and (longitudinal) load is applied, the balls 25 contact an inner face 30 of the female portion 15. A resultant (radial) force is produced and a connection formed between the male portion 10 and female portion 15. If the load is removed, the ball cage 20 is drawn back, the balls 25 lose contact with the female portion 15, and the connection separates.